The invention relates to power drives for machine elements, but more particularly, the invention relates to toothed sprockets for transmitting power to toothed power transmission belts. The sprocket is particularly directed for use in a fouling environment such as encountered with conveyor belts, harvesting equipment or snowmobile tracks.
Sprocket wheels are used to transmit power to various types of toothed belts. In special applications, the sprocket wheels are used to transmit power in fouling environments such as induced by foliage, snow, dirt, or the like. This invention is directed to such sprockets. For example, sprockets are used to transmit power to crop gathering belts as disclosed in U.S. Pat. No. 3,853,016 or snowmobile belts such as disclosed in U.S. Pat. Nos. 3,472,563; 3,575,474; and 3,756,668; or power transmission belts as disclosed in U.S. Pat. No. 3,888,132. This invention is directed primarily for powering such types of belts.
While sprockets of the type referenced are suitable for their power transmission and anti-fouling characteristics, they introduce stress problems in the belts which could cause shorter service life because of cracking; and such sprockets induce hysteresis into the belt which results in a power transmission loss. Also, integrally molded elastomeric sprockets may typically require integrally molded reinforcements at their hubs for high torque applications.
An object of the invention is to provide a sprocket which does not introduce hysteresis for those type belts with large integrally molded driving teeth.
Another object of the invention is to provide a sprocket which may be used as two replaceable halves with an optional reinforcement interpositioned therebetween for high torque applications.
Another object of the invention is to provide a anti-fouling sprocket for guiding and powering toothed power transmission belts.
The primary advantage is that longer belt lives result from the use of the sprocket of the invention than was formally realized with prior art sprockets.